This is yet another bank job, this time for the police, and it can be troublesome at first. You have to reach the tall tower (1) in front of the entrance to the Chan's gang's HQ. Walk into the neighboring building and force the door open (2) Inside, there is a color gun swapper. Choose the red paint, aim and fire it at the button above the machine, outside. Jump in there from the left side of the building (4), there is a catapult there, which will launch you onto the tower.
Now, walk over onto the rooftop of the nearby building in the park. You will not have any problems here anymore - at the back, there is a hook that will help you climb up. There, in the marked spot, you have to take a photo of the mobsters on the balcony of the red building across. Then, take another photo of the mobsters - your character will automatically face the spot, where there is the target (people wearing red sweatshirts). You have to zoom in before taking the picture. The last photo must be taken of the car (especially of its front).